Roller bit



P 1 J. s. GOODWIN 2,482,263

ROLLER BIT Filed NOV. 20, 1945 2 Sheets-Sheet l INVENTOR.

John .5. Goodwin p J. 5. GOODWIN 2,482,263

ROLLER BIT Filed NOV. 20, 1945 2 Sheets-Sheet 2 INVENTOR. Ta/2n 5- Goodwin BY w A tor-m2 Patented Sept. 2Q, 1949 ROLLER BIT John s. Goodwin, Whittier, Calif., assi'gnor to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Application November 20, 1945, Serial No. 629,881

6 Claims.

This invention has to do with a roller type well drilling bit, commonly referred to as a rock bit, being that type of bit wherein cutting action is performed by rolling toothed cutters. It is a general object of the present invention to provide a bit of the general type referred to which is highly efficient and practical for digging tough rubbery shale formations such as are commonly referred to as brown shales.

It is a general object of my present invention to provide a bit of the general type mentioned with a pair of cutters having teeth arranged, proportioned and related so that a substantial proportion of the weight or force applied during drilling causes effective penetration of the teeth into the formation while a small proportion of the weight is carried or borne by cuttings lodged between the teeth. In the ordinary cutter for bits of the character referred to the teeth are such that a substantial proportion of the drilling weight is borne by cuttings wedged or lodged between the teeth or rows of teeth, and consequently there is but a limited pressure on the teeth causing them to penetrate the formation.

It is another general object of my present invention to provide a pair of cutters for a bit of the character mentioned in which the active parts, that is, the teeth which are arranged in rows, are so arranged, proportioned, and related that the cuttings are effectively cleared from between the teeth, with the result that the cutters are maintained in condition for active operation. By my invention I employ tapered cutters and the taper and mounting of the cutters is such that as the cutters work they do not have a true rolling action but rather have substantial slippage both at their inner and outer ends, thus wiping the formation cuttings from the grooves between the teeth, with the result that cuttings are worked lengthwise of the cutters between the teeth dislodging them so that the teeth are kept cleared and do not wedge tight as is the case if provision is not made for proper cleaning.

A further object of my present invention is to provide a pair of cutters for a bit of the character mentioned in which the teeth of each cutter extend, generally, lengthwise thereof, some of them being pitched in a slightly lefthand direction while others are pitched in a slightly righthand direction, the pitching of the teeth of the two cutters of the pair being generally opposite.

Another object of the invention is to provide an improved, highly eificient and efieotive tooth formation and relationship for cutters of the general type referred to. By my present invention I provide teeth of limited length axially but which are of substantial height, and which are spaced a substantial distance apart so that they present limited points or cutting edges to penetrate the formation and afford ample clearance for cuttings.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which;

Fig. 1 is a side view of a well drilling bit embodying a. pair of rollers incorporating my present invention, parts of the bit being broken away to show in section and to better illustrate the general construction. Fig. 2 is a side elevation taken as indicated by line 22 on Fig. 1. Figs. 3, 4 and 5 are views illustrating one cutter of the pair of cutters, Fig. 3 being a side elevation of the cutter, Fig. 4 being an end view taken as indicated by line 4-4 on Fig. 3, and Fig. 5 being a view taken as indicated by line 5-5 on Fig. 3. Figs. 6, '7 and 8 are views illustrating the other cutter, Fig. 6 being a side elevation, Fig. '7 being an end view taken as indicated by line 1! on Fig. 6, and Fig. 8 being a view taken as indicated by line 8-8 on Fig. 6.

My present invention is primarily concerned with a pair of roller cutters to be employed in a well drilling bit and the cutters that I provide can be used to advantage to cut the bottom or main portion of a well bore. In an ordinary or conventional type of rock bit where there are two crossed pairs of cutters I preferably employ my invention in connection with what are commonly termed the inner cutters, since this pair of cutters extends across a substantial portion of the bottom of the well bore. In the drawings I have shown a typical application of my present invention and have there shown the invention applied to a pair-of inner cutters of a typi cal rock bit which has both inner and outer cutters.

The rock bit shown in the drawings involves, generally, a body Ill-having a tapered threaded mounting pin I I projecting from its upper end and having diametrically opposite depending side legs I2 between which the pair of inner cutters is carried. In the particular case illustrated the cutters are arranged on a common transverse axis and their inner ends are separated somewhat to accommodate a central supporting Web l3 which depends from the center of the body. The bit illustrated involves outer cutters l4 carried by depending legs l5. However, my present invention is in no way concerned with the details of these particular parts.

The pair of roller cutters thatI provide is formed by a roller cutter X and a roller cutter Y, which are slightly tapered and Which are rctatably supported between the legs l2 and also by means of the center web Hi. My present invenindicated in a general way means supporting the cutters for rotation.

B of cutter X are pitched lefthanded while the teeth of the remainingrows..of thatputter are pitched rightharided. m the case f the cutter Y the teeth of the inner row A and the adjacent intermediate row C are pitched lefthanded while the teeth of the outer row B and the adjacent row are pitched righthanded. Through thus The two cutters X and Y are. preierablysub,-.-

stantially equal in length, -in-. f faet, they ma be exactly equal in length and they are arranged so that their small ends are opposed or are adjacent n the center supporting weh li-whil'ei their large ends are adjacent the inner sides of the supporting legs l2.

The cutter X has an inner row A of'teeth an outer row 3 of teeth, and intermediate'rows' C of teeth. The cutter is similarly formed with an inner row A of teeth, an outer row B of teeth, and intermediate rows C of'teeth. The rows of teeth of the. two cutters that I have just referred to diiier in two important particulars. First, the axial extent of the teeth of thetwo inner r'o'ws differs substantially andthe axial extentof the teeth of the outer rows, diffeie'substantially, and the pitch of the teethjof the inner rows differs or is opposite whilethe pitch of the teeth, of the outer rows differs, or is opposite. In the partin ular form of the invention illustrated the teeth of the row A of cutter X. are of limited extent axially so that the row A may besaid to be narrow while the teeth of row A of cutter Y are of substantial extent axially that the row A may be said to be Wide. Through this relationship or variation between the inner rows A and A of the two cutters I gain, an overlapping Of the paths of these two rows of teeth and thepath of the row A is considerably wider than'that of the row A and consequently projects considerably beyond that of the row A. In thecase of the outer rows of teeth the row B, of. cutterX is; of considerable extent axially and, therefore, the row B is wide while the teeth of rowrBf are of limited extent axially so that the row is narrow. The outer.

rows B and B, being thus formed, have paths which overlap while-the pathof row B of cutter X projects or extends considerablyinward beyond that of the rowB" oi cutter Y.

Adjacent rows of teeth of cutter X are spaced apart by deep grooves or channels 20 and in lil ze manner adjacent rowszofteeth of cutter Y are spaced apart by deep grooves or channels 20f. In accordance with my invention the grooves M between adjacentrows of teeth or cutter X- are slightly wider thanthe crests 2| of the teeth of intermediate rows C of cutter Y, while the grooves 20' of cutter Y are slightly wider than theecrests 2| of the teeth ofthe intermediate rows Cor-cutter X. Furthermore, the intermediate rows ofteeth of the cutters X and-Y are located so that each intermediate rowof teeth of-one cutter tracks opposite a groove of the other-cutter.

In accordance with my present invention the.

teeth to the axis of' the cutter other thanlthat.

which may be incidental .t'o the cutter be'i'ng tapered-as shown in the drawings. Some ofthe rows of teeth of eachcutter-are pitched -in .,one

direction while other -rows are pitched in the op e' posite direction. fin-- the.. .partic ularl case. illustrated in the drawings the teeth of the outer row varying the pitching. of .the teeth of each cutter and relating the pitching of the teeth of the two cutter-s, the-teeth of the outer rows of the two cutters engage the formation at different angles and the-teeth of the inner rows of the two cutters engage the formation at difierent'angles, while the teeth of the intermediate rows of the two cutters do not track but engage the formation .in staggered relation and" also at varying angles all with the result that I eliminate'entirelyany tendency for the cutters tolform' a patterri'i'nto whichthe cutters fit and consequentl track in a inannerto check proper penetration of the formation.

In accordancewith the preferred; relationship 7 row A of cutterX and the outer row B of cutter Y, the crests Of-i Whi ch areshorter. In my preferred construction I space the teeth asubstantialdistance apart circumferentially, for instance,

I prefer to space the teeth approximately one and one-half to two times the depth of. the teeth. In order to accomplish this it is necessary to form fewer teeth at the si'nall endofeachcutter than at the large end. In the particulai'case illustrated I have provided-l6 teeth at the large end of each cutter; andonly lz'at thie'small end.

In. order'to' create the desired slippage .and consequeiit oleaifilflgflationl I -iilcr flot form the cutters" tobe conical; or in a manner to have'true rolling aetionmut rather tapefthem only slightly as shown in the drawings. and arrange and proportion them so that, the. plane of true rolling contact between each-cutter and the formation is approximately oheethird of 1 the length of the cutter from. the. outer end thereof. In such case points on each. cutter outward of" such; plane roll raster, all with the result that there isnot true rolling contacto'f the te'ethwiththe formation.

but rather slippage an e hseque t efiective digging action. The slippingiurtheraids in keeping. the, cutters cleaiias there is. atendency for all contribute. to. freeing. the. teeth for greater penetration and consequent, effective drilling action. I

In addition to the clahihg' action gained by the construction and relationship. that I have above. described'l'prdv'ide thebit body with general openings 30" which direct circulatin fluid onto the upper partsof the, rollers so that the rollers areefiectively'washedas they operate. By forming the teethso thatthe'iri erests are short relative to the grooves of spaces between them,

warid yet relating the rows of teeth and the grooves so the grooves are ljdiilyl slightl wider thanthe rows: otteeth, the formation is ffectively retering the formation so that there is a hi penetrating pressure to cut the formation.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims:

Having described my invention, I claim:

1. In a wall drilling bit including, a body, and a pair of tapered roller cutters carried by the body with their small ends opposed, each cutter having a plurality of spaced rows of teeth, the teeth of each row being pitched relative to the longitudinal axis of the cutter on which they occur and the row of teeth at the inner end of one cutter being wider than the row of teeth at the inner end of the other cutter and the row of teeth at the outer end of the first mentioned cutter being narrower than the row of teeth at the outer end of said other cutter, the teeth of the inner row of the first-mentioned cutter being pitched in a common direction opposite to the teeth of the inner row of said other cutter, the teeth of the last mentioned row being pitched in a common direction, the teeth of the outer row of the first mentioned cutter being pitched in a common direction opposite to the teeth of the outer row of said other cutter, the teeth of the last mentioned row being pitched in a common direction.

2. In a well drilling bit including, a body, and a pair of tapered roller cutters carried by the body with their small ends opposed, each cutter having a plurality of spaced rows of teeth, the teeth of each row being pitched relative to the longitudinal axis of the cutter on which they occur and the row of teeth at the inner end of one cutter being wider than the row of teeth at the inner end of the other cutter and the row of teeth at the outer end of the first mentioned cutter being narrower than the row of teeth at the outer end of said other cutter, the teeth of the inner row of the first-mentioned cutter being uniformly pitched opposite to the teeth of the inner roW of said other cutter in which the teeth are uniformly pitched, and the teeth of the outer row of the first mentioned cutter being uniformly pitched opposite to the teeth of the outer row of the said other cutter in which the teeth are uniformly pitched, the teeth at the inner ends of the cutters being pitched opposite the teeth at the outer ends of the cutters.

3. In a well drilling bit including, a body, and a pair of tapered roller cutters carried by the body with their small ends opposed, each cutter having a plurality of spaced rows of teeth, the teeth of each row being pitched relative to the longitudinal axis of the cutter on which they occur and the row of teeth at the inner end of one cutter being wider than the row of teeth at the inner end of the other cutter and the row of teeth at the outer end of the first-mentioned cutter being narrower than the row of teeth at the outer end of the said other cutter, the teeth of the inner row of the said first-mentioned cutter being pitched opposite to the teeth of the inner row of the said other cutter and the teeth of the outer row of the said first mentioned cutter being pitched opposite to the teeth of the outer row of the said other cutter.

4. In a well drilling bit including, a body, and a pair of tapered roller cutters carried by the body with their small ends opposed, each cutter having a plurality of spaced straight rows of teeth, the teeth of each row being pitched relative to the longitudinal axis of the cutter on which they occur and the row of teeth at the inner end of one cutter being wider than the row of teeth at the inner end of the said other cutter and the row of teeth at the outer end of the first--mentioned cutter being narrower than the row of teeth at the outer end of the said other cutter, the teeth of the inner row of the said firstmentioned cutter being pitched opposite to the teeth of the inner row of the said other cutter and the teeth of the outer row of the said first mentioned cutter being pitched opposite to the teeth of the outer row of the said other cutter.

5. In a well drilling bit including, a body, and a pair of tapered roller cutters carried by the body with their small ends opposed, each cutter having a plurality of axially spaced straight rows of teeth, the teeth of each row being pitched relative to the longitudinal axis of the cutter on which they occur and the row of teeth at the inner end of one cutter being wider than the row of teeth at the inner end of the other cutter and the row of teeth at the outer end of the first mentioned cutter being narrower than the row of teeth at the outer end of the said other cutter, the teeth of the inner row of the first-mentioned cutter being uniformly pitched opposite to the teeth of the inner row of the said other cutter in which the teeth are uniformly pitched, and the teeth of the outer row of the first-mentioned cutter being uniformly pitched opposite to the teeth of the outer row of the said other cutter in which the teeth are uniformly pitched, the teeth at the inner ends of the cutter being pitched opposite to the teeth at the outer ends of the cutters.

6. A well drilling bit including a body and a pair of uniformly tapered coaxial roller cutters carried by the body with their small ends opposed, each cutter having a plurality of spaced rows of teeth, the teeth of each row being pitched relative to the longitudinal axis of the cutter on which they occur, and the teeth of one cutter being pitched opposite to those of the corresponding teeth of the other cutter, the row of teeth at the inner end of the one cutter being wider than the row at the inner end of the other cutter and the row of teeth at the outer end of the first mentioned cutter being wider than the row at the outer end of said other cutter, the taper of the cutters being related to their length and diameters so the plane of true rolling contact of each cutter with the formation being cut is removed from the outer end of the cutters a distance substantially equal to one third of the length of the cutter.

JOHN S. GOODWIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,412,003 Hughes Apr. 4, 1922 1,896,295 Evans et a1. Feb. 7, 1933 2,122,759 Scott July 5, 1938 2,165,584 Smith et al. July 11, 1939 2,171,057 Crum Aug. 29, 1939 2,182,903 Phipps Dec. 12, 1939 

